I was wondering about how are transactions ordered in the block. I was checking three different transactions, two of them made by sniper bots and I don't know where lies the difference and why one is slower than the other.

  1. Open trading - Gas price of 26.180243597 gwei | 6th position in the block
  2. First sniper buy - Gas price of 25.880243597 Gwei | 7th position in the block
  3. Second sniper buy - Gas price of 26.180243597 gwei | 334th position in the block

And thinking about it, first sniper paid less gas than the second one, so after open trading second sniper buy should be before first sniper buy. And here it wasn't the case. I am wondering why, how is it possible that openTrading() transaction was submited in 6th position in the block, and the first sniper was in the 7th. Second sniper was at position 334 tho, and this I also have no idea why. How are these transactions ordered?

1 Answer 1


Usually, transactions are ordered by gas and gas price but this is not a definite rule. A validator node can choose whatever transaction they want to put into a block, in any order, without concern about profitability.

In this case, the validator is an MEV validator. You may have heard about Flashbot and bloXroute. They have their own validator network to prioritize their transactions over regular transactions. The sender pays an extra fee directly to validators.

  • Yeah, I was messing around with Flashbots just now, but I'm still wondering. Is it possible to use flashbots or bloxroute to "place" the transaction so close to the openTrading() one? Let's say the openTrading() happens at position 200 (we don't know that yet until block is validated), can we bribe the validator to put our transaction at position 201?
    – Kacper
    Commented Mar 9, 2023 at 8:49
  • AFAIK bloxroute and flashbot don't support anything like this. Commented Mar 9, 2023 at 9:08

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.